Figure 2

Schematic representation of the underlying chemistry of lucigenin chemiluminescence. Luc²⁺ = lucigenin; LH^+• = a lucigenin radical created by the one electron reduction of Luc²⁺. The reaction of LH^+• with oxygen generates O₂^-•. The latter then participates in an oxygenation reaction with LH^+• generating a dioxetane that decomposes with the generation of chemiluminescence. Any entity that can bring about the one electron reduction of lucigenin can potentially create a redox cycle in the presence of oxygen that produces high levels of O₂^-• and chemiluminescence. It is impossible to distinguish the relative contribution of such probe-dependent and cell-dependent chemiluminescence. Hence data obtained with this probe should be interpreted with caution.